Dietary Metabolizable Energy Research Articles

Effects of variation in dietary energy concentration of starter and finisher diets on broiler production

Least-cost starter and finisher broiler diets at five levels of metabolizable energy (ME) concentration were formulated. The diets were fed in selected combinations of starter and finisher energy concentration to batches of broiler chickens to 1650 g. Performance data were recorded and it was found that best biological efficiency was obtained by feeding starter-finisher diets with ME concentrations in the range 12.6 to 13.8 MJ kg-1. However, best economic results were obtained from diets with energy concentrations somewhat below these levels, at approximately 12.2 to 12.5 MJ kg-1. There was no evidence that ME of the starter diet influenced the ME concentration of the finisher diet required for optimal performance.

The Use of Bile Salts to Improve Absorption of Tallow in Chicks, One to Three Weeks of Age

Apparent fat absorption was 39.6 and 68.2% in chicks 4–7 and 14–19 days of age, respectively, fed purified-type diets with 8.2% tallow (TLW). Cholic acid (C.A.), chenodesoxycholic acid (Ch.A.) and taurocholate, sodium salt (T.A.) at .025 and .05% increased significantly the apparent absorption of fat by 8.4 percentage units in chicks 4–7 days of age, and as much as 10 percentage units in chicks 14–19 days of age. No significant increase in metabolizable energy of diets was detected. C.A. was fed to S.C.W.L. hens at graded levels up to .2% in corn-soy diets containing either 4 or 8% TLW or hydrogenated soybean oil. No improvement in fat absorption or M.E. was detected in these hens which absorbed 86–89% of the fat. The data indicate that bile salts appear to be effective in improving the absorption of saturated-type fats only in young chicks whose absorptive mechanism for fat is not fully developed.

Plasma Amino Acids of Infants Consuming Soybean Proteins with and without Added Methionine

Fasting plasma free amino acids were determined in 54 convalescent malnourished infants: seven infants while consuming a diet based on isolated soybean protein, containing 4.0% to 5.3% of dietary metabolizable energy (calories) as protein (A), 20 at 6.4% to 6.7% protein calories (B), 23 at 6.4% to 6.7% protein calories with added DL-methionine (C), and four with 8.0% to 12.3% protein calories (D). There were no differences in total amino acid concentration (TAA) among the four groups; the molar fraction of essential amino acids (EAA:TAA) was lower for group A; there were no differences among the four groups in Lys:EAA or 1/2 cystine:EAA ratios or in Met concentration. Met:EAA was higher in C than B, with considerable overlap of individual values. In 10 of 13 infants who were represented in both B and C, Met concentration and Met:EAA ratio were higher in group C. Fasting plasma AA levels are not consistently reliable for field or clinical assessment of dietary Met adequacy. Fasting and postprandial (3- and 4-hour) plasma AA were determined in 29 infants: in 12 the preceding diet and the test meal were both Met-deficient with less than 6.7% protein calories (E), in five the preceding diet was milk-based but the test meal was Met-deficient at less than 6.7% (F), in five the preceding diet and test meal were based on isolated soybean protein at less than 6.7% with DL-Met added (G), and in seven the test meal was soy-based with greater than 9.0% protein calories (H). Plasma Met concentration and Met:EAA fell significantly at 3 and 4 hours in groups E and F, but not in groups G and H, suggesting that a postprandial fall in Met:EAA ratio can be used to identify dietary Met deficiency in field situations.

Effects of dietary energy concentration on production of broiler chickens

Eight least-cost diets with a determined range of metabolizable energy (ME) concentrations from 9.3 to 14.3 MJ kg-1 were formulated. Each diet was offered for about 12 weeks to two pens of about 100 broilers of each sex. Observations on feed consumption, liveweight and mortality were made weekly for each pen. Dressing percentages were recorded for samples of ten birds from each pen at two different Iiveweights. As ME concentration of the diets increased, birds grew faster and required less food, in terms of both total weight and total energy, to reach specified liveweights, although these effects were not marked when the dietary ME concentration was above 13.5 MJ kg-1. Feed conversion was less efficient at the same ME concentration when birds of each sex were taken to higher liveweights. Dressing percentage increased with increases in dietary ME concentration for males, but for females it tended to decline at the highest energy concentrations. Mortality was the same (2 per cent) on all diets.

Sites of digestion in the calf. I. The digestion of diets containing barley and wheat chaff supplemented with soya bean meal or urea

Four Friesian bull calves were fitted with re-entrant duodenal cannulae within 1 week of birth. From 13 weeks of age the calves were fed on one of three diets all containing 17% crude protein. Diet A contained barley, 15% wheat chaff and soya bean meal, diet B barley, 15% wheat chaff and urea, and diet C barley, 45% wheat chaff and soya bean meal. The diets were given for 2 weeks, and on the last day of each feeding period total collections were made of the digesta leaving the abomasum over a 12 hr period. The diets were then changed so that each calf was offered each diet twice. The total apparent digestion of the organic matter in the diet containing 45% wheat straw was less than that of those containing 15% wheat straw. This was due to less digestion in both the stomach and hindgut. The flow of nitrogen from the abomasum, expressed as a percentage of the nitrogen intake, was less when the calves were fed on the diet containing urea (B) than when they were fed on those containing soya bean meal (A and C). Also, a larger proportion of the nitrogen was of microbial origin when they were on diet B. The proportion of essential amino acids in the total amino acids flowing from the abomasum was greater than that in the total amino acids present in all diets. Also, the apparent digestion of essential amino acids in the hindgut was greater than that of non-essential amino acids. It is calculated that methionine and threonine may be limiting for the growth of calves given diets A and B, while dietary metabolizable energy intake was probably the first factor limiting the growth of calves on diet C.

The Use of Polyethylene as an Indicator in Determination of Metabolizable Energy of Diets for Japanese Quail

Polyethylene can be used as an inert indicator in the determination of metabolizable energy. Methods are described for its quantitative determination. Metabolizable energy of diets containing glucose, fructose and sucrose was higher in one-week old quail than six-week old quail.

Dietary energy content and floor space relationships for optimal growth and efficiency of broilers

Commercial broilers, kept in small, fixed-size pens, were allowed 310, 370, or 460 cm2 of floor space per bird started at one day of age, in a windowless controlled environment house. At each stocking density birds were offered diets with 12.5, 12.9, or 13.4 MJ kg-1 of metabolizable energy from 41 to 64 days of age. Male and female broilers grew more slowly (P < 0.05) when offered the lowest energy diet. They were heavier (P < 0.05) when allowed 460cm2 of floor space per bird. Total output on the basis of liveweight produced per unit of floor space over 64 days of age was largest in the most densely stocked pens. Optimal dietary metabolizable energy concentration was approximately 12.9 MJ kg-1; however, reasons for varying this recommendation are discussed.

Age and Breed Difference in the Effect of Dietary Protein on Carcass Fat Deposition of the Chicken

It has been reported that starting chicks and growing meat-type chicks can easily become fatty or lean by simply changing dietary levels of protein, but, in striking contrast, dietary protein levels have little effect on abdominal fat content of laying hens. In this paper, is reported the effect of dietary levels of energy and protein on the body fat deposition of growing chicks of both sexes of two strains at various ages.Both males and females of White Leghorn or meat-type cross-breds were sacrificed at 4, 6, 8, 12, 16 and 20 weeks of age for abdominal fat determination. Abdominal fat was determined because it has highly significant correlation with body fat deposition. Therefore, the latter can be estimated from the former. Except those sacrificed at 4 and 6 weeks of age, 24 males and 24 females were moved from the farm of National Institute of Animal Industry into the chick room kept at constant temperature of 20°C., and divided into 16 groups of 3 chicks each. One of the 4 experimental diets was fed to duplicated lots of males and females for 25 days before the determination of abdominal fat. Two-week-old chicks were reared in an electrically heated battery brooder for 2 weeks in the chick room on the experimental diets and sacrificed at 4 and 6 weeks of age as mentioned above.The combination of 2 levels of crude protein and 2 levels of metabolizable energy (kcal/g air-dry diet) prepared 4 experimental diets. Their contents were determined to be 14.8%-3.00kcal/g, 14.9%-2.52kcal/g, 20.4%-2.97kcal/g and 20.2%-2.47kcal/g, respectively.Effect of dietary energy and protein levels on abdominal fat deposition was analyzed statistically at various ages, and following results are obtained:1) Higher dietary energy level resulted in more deposition of abdominal fat in all stages of growth, except females at 20 weeks of age. Females at 20 weeks of age deposited large amount of abdominal fat even on low energy-high protein diet, presumably related with the sexual maturity of females.2) Higher level of dietary protein depressed fat deposition of White Leghorn chicks of both sexes at 8 weeks or younger and of meat-type chicks of both sexes at 12 weeks or younger. Little difference in abdominal fat deposition was observed between the chicks older than mentioned above, fed either high or low protein diets. It was also observed that the effect of high protein diet on fat deposition disappeared earlier in females than in males. These findings suggest that the depressing effect of dietary protein on fat deposition is related with sex hormones.3) In young chicks, on which the depressing effect of dietary protein on fat deposition was seen, the increase in dietary protein level by 5.5% approximately corresponded to the decrease in dietary metabolizable energy by 0.5kcal/g, in other words, one g of dietary protein apparently corresponded to -9.09 (=0.5/0.055) kcal of metabolizable energy, which closely resembles to -9.44kcal reported previously.4) Body fat deposition is related to actual intake of energy and protein rather than to their dietary content. However, it was revealed that change in feed intake under the experimental condition was so small that it was negligible in the discussion on fat deposition, except the change in feed intake of young White Leghorn chicks at 6 weeks of age. Dietary protein level of 14.5% seemed to be too low for young chicks and feed intake of the low protein diet was less than that of the corresponding high protein diet. This difference in feed intake had influence on fat deposition.

The Effect of Energy Supplied from the Diet and from Environment Heat on the Response of Chicks to Different Levels of Dietary Lysine

Experiments were conducted to study the effect of differences in energy input from both diet and from environmental temperature on the response of chicks to diets containing different levels of lysine. The basal diet was based on wheat and sesame meal. Dietary metabolizable energy was adjusted with ground cellulose and lard. Environmental temperatures between 18.3 and 31.1°C. were employed. From the results it was concluded that (1) energy input as heat can substitute for a portion of the metabolizable energy which is expended to maintain body temperature, (2) the optimum dietary level of effective protein is dependent upon the combined energy input from environmental temperature and dietary metabolizable energy and (3) aggravation of the depressing effect of dietary amino acid imbalance on feed consumption and growth rate occurs with increased energy supply to the birds either as heat or as dietary metabolizable energy.

EFFECTS OF POPULATION DENSITY ON ENERGY UTILIZATION, INTESTINAL DISACCHARIDASES, AND ADRENAL FUNCTION IN HENS

Two experiments were carried out with laying hens to determine the effect of overcrowding stress on reproductive performance and on certain other parameters that might be expected to be affected and thus be useful indices of this type of stress. The first experiment consisted of eight treatments in a factorial arrangement with four bird densities of one, two, three, or four birds in 30.5 × 45.7-cm (12 × 18″) cages and two levels of dietary energy. The second experiment involved three bird densities of one, three, and five birds in 30.5 × 45.7-cm cages fed a single diet. There were four replicate cages per treatment in both experiments. Feed consumption, weight gain, and egg production were not significantly affected by the population densities employed in experiment 1. In experiment 2, increasing bird density significantly reduced egg production, and hens maintained at five per cage suffered a net loss of body weight. In neither experiment was energy utilization affected by crowding since the dietary metabolizable energy values remained constant. In both experiments mucosal maltase and sucrase activities were significantly increased with increasing bird density when birds were fed diets of relatively normal starch content. Plasma-free fatty acids, total fatty acids, and triglyceride levels were not significantly affected by population density, nor were the oleic–linoleic–arachidonic acid levels expressed as percentages of total fatty acids. It would thus appear that lipid metabolism remained relatively normal in hens subjected to overcrowding stress. The levels of peripheral plasma corticosterone and adrenal corticosterone increased in a linear fashion in both experiments with increasing bird density. It would appear that plasma and adrenal corticosterone levels might be useful indices of overcrowding stress in hens.

Influence of Metabolizable Energy on Condition and Reproduction of Pheasants

Influence of Metabolizable Energy on Condition and Reproduction of Pheasants

The utilization of the metabolizable energy of diets of different protein content by the milk-fed lamb

SUMMARYNineteen male cross-bred lambs, aged between 2 and 5 days, were allotted to each of three dietary treatments for an experimental period of 3 weeks. The protein contents of the diets (on a dry-matter basis) were 12·0% (diet A), 28·5% (diet B) and 45·5% (diet C). The diets were fed as artificial milks that contained 15% total solids, and the energy intakes of groups of lambs within each dietary treatment varied from below maintenance to ad lib.Metabolizable energy (ME) as a percentage of the gross energy was constant for all diets, at all levels of energy intake, at 94·3 ± 0·3%. ME intake was linearly related to energy retention above maintenance with all diets. There was a significant linear decrease in the net efficiency of ME utilization as the protein content of the diet increased. However, the individual regressions did not differ significantly from the common regression coefficient of 0·686 ± 0·018, i.e. a net efficiency of 68·6 ± 1·8%. The individual coefficients were 0·740, 0·679 and 0·634 for diets A, B and C respectively.The ME requirement for energy equilibrium (maintenance) of lambs given diet B (100·4± 11·7 kcal/kg0·73 day) was significantly lower than that of lambs given diet A (126·4 ± 14·3) or diet C (119·2 ± 15·6). The energy costs of fat and protein deposition, calculated by multiple regression analysis of the pooled data, were 11·1 kcal ME per g fat and 8·5 kcal ME per g protein respectively.

The Effect of Antibiotic Supplementation on Growth and Energy Utilization of Chicks

SEVERAL studies on the effect of antibiotic supplementation on energy metabolism showed no agreement as to the influence antibiotics have on the metabolizable energy derived from the diet.Nelson et al. (1963) reported that some, but not all, of the antibiotics they investigated increased the metabolizable energy content of a practical chick diet and that this increase in metabolizable energy content was correlated with growth stimulation and a decrease in intestinal weight. Gorril et al. (1960) concluded that an increased energy digestibility coefficient in swine was related to increased growth due to antibiotic supplementation.Sibbald et al. (1961), in studies with both chicks and poults, found no significant effects on dietary metabolizable energy content attributable to antibiotic additions to the diet. Slinger et al. (1962) reported that the addition of antibiotics to turkey starting diets had no influence on their metabolizable energy values.The experiments reported here were part of…

Effects of Moderate Lysine Deficiency on Digestibility and Metabolisable Energy of Diets and on Nitrogen Retention and Uric Acid Excretion in Chicks

Effects of Moderate Lysine Deficiency on Digestibility and Metabolisable Energy of Diets and on Nitrogen Retention and Uric Acid Excretion in Chicks

Navy beans (Phaseolus vulgaris) as a protein source in layer diets

The effects of raw versus steamed navy bean (Phaseolus vulgaris) meal, in diets with and without methionine supplementation, on egg production, egg weight, body weight, pancreas weight, mortality, feed consumption and conversion, and energy and nitrogen utilization were determined with laying hens. As the level of raw navy bean meal in the diet increased, egg mass production and body weight gain decreased. Declines in production were largely overcome by steaming the bean meal. Methionine supplementation of both raw and steamed meal diets had no effect on performance. Changes in dietary metabolizable energy and nitrogen retention are discussed in relation to bird performance.

Response of laying hens fed on a restricted isocaloric intake basis to oil supplementation of a low‐fat ration

AbstractDept. of Agricultural Chemistry, Queen's University, Belfast and Ministry of Agriculture, N. IrelandTwo experiments are described in which varying levels of corn oil or cod liver oil were added to the diet of birds previously maintained from one day old on a low‐fat cornflour‐based diet containing 0–35% linpleic acid. All diets were fed at three different metabolisable energy (ME) intake levels, the birds being fed a weighed quantity of food daily.Neither ME intake nor dietary corn oil or cod liver oil supplementation had any significant influence on egg size. Increasing levels of dietary ME increased the number of eggs laid, the response being very rapid and occurring within the first 28 days. Any effect of dietary com oil was exerted mainly through the size of eggs laid, although these differences in egg size were not great enough to attain statistical significance. The response to dietary corn oil was not as rapid as the response to dietary ME and no significant effect of corn oil was observed until the second 28‐day period. Dietary corn oil increased the efficiency of conversion of dietary ME to egg product but dietary cod liver oil was without effect.

Separation of Soybean Whey into Fractions with Different Biological Activities for Chicks and Rats

Using a batch fractionation procedure on DEAE cellulose, 4 fractions of soybean whey were prepared and studied for biological activity with chicks and rats. All fractions prepared had trypsin inhibitor activity but hemagglutinin activity and intraperitoneal toxicity for rats was concentrated in one fraction. The fractions differed in relative stimulation of the pancreas of chicks to enlarge and the gallbladder to contract. Differences were also noted among the fractions in their effects on chick growth, fat absorption and dietary metabolizable energy value. Many of the effects caused by the soybean fractions appeared to be related to several components rather than to one specific fraction.

Effects of animal fat and of low ratios of protein to metabolisable energy on the utilisation of dietary energy by medium‐ and fast‐growing strains of poultry

AbstractIn three experiments each involving 16 groups of 12 birds, diets having normal to low ratios of crude protein to metabolisable energy were fed, for the first 12 weeks of life, to cockerels of a Rhode Island Red X Light Sussex cross and a modern commercial fast‐growing hybrid. Dietary ratios of crude protein to metabolisable energy were lowered by adding either maize starch or animal fat to a diet which was based on cereals and was, by calculation, adequate in all known nutrients. The efficiency with which metabolisable energy was converted to tissue energy was assessed by a carcass analysis technique which also allowed a study of the effect of diet on body composition.In both strains of bird, diets in which the ratios of crude protein to metabolisable energy had been lowered considerably below that corresponding to the 20% protein and 2.9 Mcal. metabolisable energy per kg. recommended by the (U.S.A.) National Research Council, gave rise to a greater metabolisable energy intake and greater loss of this energy, mainly as heat, per unit of live body weight. Deposition of body fat was also greater than in birds fed normal diets. The relative importance of heat loss to the environment and deposition of body fat, for disposal of excess energy ingested through overeating to compensate for inadequate concentrations of amino‐acids in the diet, may be influenced by breed and the proportion of fat in the diet. No significant differences were found among diets in the percentage utilisation of dietary metabolisable energy for tissue energy production and it may be that the differences found between strains arise solely from differences in dietary energy intake. Whatever the diet, the modern fast‐growing type of bird consumed more feed and therefore energy and made about 30% greater live‐weight gain with about 40% greater tissue energy gain over 12 weeks than the Rhode Island Red X Light Sussex type.

Factors Affecting the Metabolizable Energy Content of Poultry Feeds

Abstract LITTLE is known about the effect of protein quality on dietary metabolizable energy (M.E.) values. Baldini (1961) has claimed that a methionine deficient diet contained more M.E. than did the same diet supplemented with methionine; however, Carew and Hill (1961) were unable to confirm this finding. Sibbald et al. (1962a) found the effect of methionine supplementation to be small and variable while Sibbald and Slinger (1962a) observed that methionine supplementation of soybean oil meal did not change its M.E. content. Indirect evidence of a lack of effect of protein quality on M.E. is provided by the reports of Sibbald et al. (1962b) and Sibbald and Slinger (1962a) who studied the effects of level of dietary inclusion on the M.E. values of cereal grains and high protein feedingstuffs. In theory M.E. values corrected to nitrogen equilibrium should not be influenced by protein quality. As protein quality changes there is a change…

Effect of Dietary Protein and Energy Levels on the Growth Rate, Feed Efficiency and Carcass Composition of Chicks

Feeding day-old White Leghorn male chicks 9 different diets for 4 weeks with the orthogonal composite design, we studied the relationship among dietary protein, energy levels and chick’s responses. The ellipsoid relationship has been found fitted to describe the relationship between dietary composition and weight gain or feed efficiency of chicks, whereas declined planes are fitted to show the relationship between dietary composition and carcass protein or fat levels of chicks. Dietary protein level has great influence on nitrogen retention, but dietary energy level has little effect. The linear relationship between total digestible nutrients and metabolizable energy in diets is presented.